The impish expression; the muffled laugh: Alan Uomoto knows he has
secured a place in the early lore of one of the world's most ambitious astronomy
projects.

Delight overtakes him.

"I thought about writing a book," Uomoto says, from his office in the Bloomberg
Center for Physics and Astronomy.

After all, The Johns Hopkins University has just saved the most ambitious
sky-mapping venture in history.

***

The problems began three years ago for his colleagues with the Sloan
Digital Sky Survey, a cooperative project of seven not-for-profit research
institutions in the United States and Japan, as they constructed technology for
a comprehensive census of the universe.

One of the two telescopes failed.

At the time, no one worried because the faulty 24-inch 'scope was the
smaller of the two, used only to calibrate a more complex, more distinguished
2.5-meter wide-angle telescope, which would do the actual mapping.

"The little telescope was ignored by leading scientists in the program
because, after all, it's a little telescope," said Uomoto, a research scientist
who developed the spectrographic equipment for the project. "It was needed just
to identify calibrator stars. What could possibly go wrong?"

By 1997, after installation at Apache Point Observatory in New Mexico,
the diminutive calibrator - called an Autoscope - still did not work, and the
company that built the telescope quit answering calls. Uomoto did some quick
detective work, phoned astronomers in Florida and Massachusetts, who also had
attempted to use small autoscopes purchased from the company, and asked a few
pointed questions.

Everyone told the same story: In each instance, a telescope was partially
installed and never worked.

***

When the manufacturer declared bankruptcy, the Sloan team decided to fix
the telescope themselves. After all, a Herculean effort to map a quarter of the
entire sky and
determine the positions and radiance of more than 100 million celestial objects
would never succeed without an effective calibrator.

"We could see that the telescope was never engineered correctly," Uomoto
explained. "It was made with incorrect materials, and there was no way to
imagine it
performing well enough for a long enough time to be useful. But still, when you
first looked at it, you thought, 'All I have to do is wire up this encoder to
make it happen.' So you wire up the encoder and realize--oh, the board on the
encoder needs modifications. You fix that, and then you realize, 'If I fix the
board, the mounting plate has to move a little bit this way.' It went on and on
and on and on."

Sloan dedicated one full-time person to solve the problem and another team
member spent most of his time augmenting the salvage operation.

Finally, late last year, director of project development Jim Crocker, who is
also a Hopkins astronomer, polled the team and asked if anyone believed the
telescope would last the life of the project. No one did.

In December of '97, the team elected to, as Uomoto says, "chuck it."
With less than a year before the big telescope was scheduled to gather "first
light" from

the observatory, Uomoto and his colleagues searched for a new
instrument. The most prominent manufacturers said they could build one in 14
months. A number of small telescopes around the world had been decommissioned
and might have been useful, but none would fit inside the small observatory
building in New Mexico.

"So what do you do?" he asked.

***

Atop the Bloomberg building sat a small telescope, a little workhorse used
mostly on Friday nights when the department invited the public to drop by for
stargazing. Since 1993, when Uomoto first installed it, Bloomberg's 'scope had
also survived the occasional use and abuse of students who sought its clear eye
to complement their classwork.

One day, Uomoto finally fished for a tape measure and went to the roof.

If he could just knock out a five-foot concrete pier and plant a wedge under the
mount to make up for the difference in latitude between Baltimore and New Mexico.

It worked.

"I actually thought about using this telescope on the project a few
years ago," Uomoto noted. "It does so much better than the one we had out there.
But I couldn't figure out the practical aspects of making the switch, and I also
knew if I suggested it, I'd get the job. As it turns out, I got the job,
anyway."

In July, Uomoto, a few colleagues and technicians made the sacrifice.
They unbolted their precious telescope, dismantled it, and trucked the
instrument off to Apache Point. A number of them, including Uomoto, traveled to
New Mexico in August to begin the installation.

The Hopkins' telescope has been retrofitted recently with new optics and
is being tweaked for full service sometime next month. Soon it will be
positioning the big
telescope on the brightest stars and galaxies in the universe, identifying
millions of galaxies for compilation in a celestial catalogue that will rival
the Library of Congress and improve the quality of astronomical research for
years to come.

***

The good news is that Hopkins' old telescope is now working at Apache
Point and being readied for its work for scientists who want to explore critical
questions about the nature and evolution of the universe. Its title has been
cleanly transferred to the Astrophysical Research Consortium, which runs the
Sloan Digital Sky Survey, and ARC has purchased a new--and improved--telescope
for the rooftop of the Bloomberg Center.

Of course, nothing's perfect.

"Lately we've had a little trouble with a detector cooler on the large
telescope," said Uomoto, whose office is still littered with the flotsam of
telescope hardware left behind by the westward move.

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